Circuit Board Testing - Scotsman FME1200 Service Manual

CIRCUIT BOARD TESTING:

These procedures require the machine to be connected to the power supply. The voltages of the
electronic circuit are very low, but HIGHER VOLTAGES ARE PRESENT IN THE UNIT. Do not touch
anything but the tester while the unit is being checked out. Make all connections to the circuit board with
the ELECTRICAL POWER OFF.
INSTRUCTIONS FOR USING TESTER (Optional, order part no. A33942-001)
(These instructions assume that the unit will not run, and prior investigation of electric power, controls,
and mechanical parts indicates that the electronic circuit may be at fault.)
If the "Reset" indicator (located in the "reset" switch) is off and the "NO WATER" indicator is lit, but
inspection shows that the water level in the reservoir is above the top of the water level sensor, OR the
"BIN EMPTY" indicator is off while inspection shows that the ice level sensors are properly aligned, clean
and not obstructed, use the tester as follows:
Bin Control Note: All testing is done with the
electrical power on, the master switch on, and all
reset switches ''reset''.
1. Unplug ''photo trans'' and ''LED'' connectors from
the circuit board.
2. Plug ''photo trans'' and ''LED'' connectors from
the tester into the circuit board.
a. Move the ''bin full'' switch on the tester to Full.
The light on the tester should be ON.
If the light on the tester is not on, the circuit board
should be replaced.
SWITCH TO
''FULL ''
PHOTO TRANS
LED
LIGHT GOES
ON
January 1995
Page 31
NME950 & FME1200
b. If the light on the tester IS on, move the ''bin
full'' switch to Bin Empty. The light on the tester
should go OFF, and the Bin Empty light on the
circuit board should go ON.
If the Bin Empty light is ON, wait 10-20 seconds for
the machine to start, if the machine starts, replace
the ice level sensors.
If the Bin Empty light does not come ON, the
circuit board should be replaced.
SWITCH TO
''BIN EMPTY ''
LIGHT GOES
ON
LIGHT
GOES OFF